Gun sighting and training apparatus



mg. 3, 1948. w s 2,446,316

GUN SIGHTING AND TRAINING APPARATUS Filed Sept. 14, 1942 4 Sheets-Sheet 1 INVENT OR. BERNARD DWILLIS, DECEASED BY W WAlIER OWEN. EXEGUTOR WQMM,

1948. B. D. WILLIS 2,446,315

GUN SIGHTING AND TRAINING APPARATUS Filed Sept. 14, 1942 4 Sheets-Sheet 2 INVENTOR. BERNARD n WILLIS, DECEASED BY w WALTER OWEN, EXECUTOR ATTORNEYS Aug. 3, 1948. B. D. WILLIS 2,446,316

GU SIGHTING AND TRAINING APPARATUS Filed Sept. 14, 1942 4 Sheets-Sheet 3 Aug. 3, 1948. B. D. WILLIS 2,445,316

GUN swarms AND TRAINING APPARATUS Filed Sept. 14, 1942 4 Sheets-Sheet 4 FIG? CONTROL 0 EVIOE Has.

CONTROL DEVICE DEVICE INVENT OR. BERNARD D. WILLIS DECEASED BY Wm WALTER OWEN. EXECUTOR m m M M ATTORN EYS Aug. 3, 1948 ED STATES OFFICE GUN SIGHTING AND TRAINING APPARATUS Application September 14, 1942, Serial No. 458,295

18 Claims.

The present invention relates to fire control apparatus for ordnance pieces and, more particularly, to improvements in apparatus for controlling the pointing of a gun from a remote point.

It is an object of the present invention to provide improved fire control apparatus which is simple in arrangement, easy to operate, and positive and reliable in its operation.

It is another object of the invention to provide improved apparatus of the character described which is so arranged that the only operation required on the part of an operator to bring the gun to bear on a target is that of manually manipulating a light sighting piece.

According to another object of the invention, provisions are made in the apparatus for causing the gun to follow the movement 01' the sighting piece and for automatically stopping movement of the gun when it is brought to bear in the direction established by the line of sight we sighting piece.

In accordance with another object of 'the invention, movement of the gun is automatically initiated in response to movement of the sightlng piece from one position to a new position.

According to a further object of the invention,

the sighting piece is equipped to project a light beam along the line of sight thereof and light sensitive exploring elements arranged to be contion, provisions are made in the apparatus for preventing changes in the temperature of the exploring elements and changes in the intensity of the light surrounding these elements from falsely causing movement of the gun.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the specification taken in connection with the accompanying drawings in which Fig. 1 illustrates in partial schematic form the mechanism of a gun which may be controlled by apparatus constructed in accordance with the present invention; Fig. 2 is a side view partially in section of the control apparatus .provided to control the gun shown in Fig. 1; Fig. 3

2 is an elevational view of the apparatus shown'ln Fig. 2; Fig. 4 is a detailed sectional view of the sighting piece 25; Fig. 5 is a detailed sectional view taken on the line 5-4 of Fig. 4; Fig. 6 is a cross-sectional view of the exploring band 20 or 21 and the balancing band He or 21a; Fig. 7 is a circuit diagram showing how the control apparatus and the driving means for the gun are electrically interconnected; Fig. 8 is a detailed sectional View taken on the line 8-8 of Fig. 4; and Fig. 9 is a sectional view taken on the line 9-9 of Fig. 8.

Referring now more particularly to Fig. 1 of the drawings, the gun there illustrated may be of the heavy type now commonly used in aircraft defense installations. Briefly considered. the gun comprises a barrel III which is mounted for rotation with a shaft ll journaled in the upstanding ends of a pedestal I2. This pedestal is supported for rotation on a heavy cup-shaped base l3 which may be fixedly mounted in a suitable gun emplacement. More specifically, the upper, inner edge of the base It is cut away to provide a shoulder I3a which carries a ball race M. Anti-friction ball bearings It held between this race and a ball receiving channel cut in the underside of the pedestal I! are provided to permit the pedestal to be easily rotated relative to the base It. Similar anti-friction bearings may be used between the shaft II and the upstanding ends of the pedestal I: to facilitate rotation of the gun barrel H) in elevation with respect to the pedestal. shaft ll, thereby to change the angle of elevation of the gun barrel l0, a. driving mechanism is provided which comprises a worm gear It rigidly mounted upon one end of the shaft II. a driving worm l1 and a pair of alternating current motors l8 and I3 which are suitably mounted upon opposite sides of the pedestal l2. Prefera'bly. the rotors of the two motors l9 and it are both carried by the single worm shaft Fla and this shaft is provided with an extension llb through which an auxiliary drive connection may :be made in the manner pointed out below. For the purpose of imparting rotary movement to the pedestal l2, thereby to change the traverse of the gun barrel ID, the pedestal is provided with a downwardly extending cylindrical portion Ila having a worm gear 20 suitably mounted thereon.

For the purpose of rotating the' Rotary movement may be imparted to the gear 20 by means of two additional alternating current motors 2| and 22 which are suitably mounted within the cup-shaped recess of the base it. The rotors of these two motors are mounted upon a worm shaf-t 23a which carries a worm 23 that meshes with the worm gear 20 and is provided with an extension 23b. From the above explanation it will be understood that by selective energiz'ation of the two motors l6 and |8 the gun barrel I may be rotated in either direction relative to the axis of the shaft i More specifically, these motors are arranged to drive the worm shaft Na in opposite directions so that if the motor l8, for example, is energized, the gun barrel I0 is pivoted in a clockwise direction relative to the axis of the shaft II to increase the elevation thereof, whereas if the opposite motor I9 is energized, the gun barrel is pivoted in the reverse direction to decrease the angle of elevation thereof. It will also be understood that by selective energization of the two motors 2| and 22 the pedestal l2 may be rotated in either direction about its axis of rotation to alter the traverse of the gun. To this end, the motor 2| may be arranged to rotate the pedestal |2 in a counterclockwise direction relative to its axis while the motor 22 is arranged to rotate the pedestal in a clockwise direction about its axis. Since the breech and firing mechanisms of the gun form no part of the present invention, the details of these mechanisms have not been shown. It is pointed out, however, that the gun is equipped with an electromagnetically actuated firing mechanism such that the firing as well as the pointing of the gun may be controlled from a remote point.

Referring now more particularly to Figs. 2 an 3 of the drawings, the apparatus there illustrated is provided for controlling the elevation and traverse of the gun shown in Fig. 1 of the drawings and may be located at any desired point remote from the gun emplacement. Generally considered, this apparatus comprises a sighting piece 25, an elevation finding loop or exploring band 26 and a direction or traverse finding loop or exploringband 21. More specifically, the direction finding loop 21 is fixedly mounted upon the two upstanding columns 26a and 28b of a frame 28 which is supported for rotation ona base 29. This base may, in turn, be supported in a concrete supporting structure 30. The base 29 is provided with a hollow centrally disposed pedestal 3| and also supports an operator's platform 32. This platform has mounted thereon, on either side of the pedestal 3|, two bracket pieces 33 which, at

elevation finding loop 26. More specifically, the bracket pieces 33a and 33b are rounded at their upper ends to provide bearing surfaces for the adiacent inwardly curved end surfaces of the loop 26. The bracket piece 33b is provided with a pivot pin 34 which extends through an opening provided in an assembly plate 35 secured to the lower end of the loop 26 as viewed in Fig. 3 of the drawings. The other end of this loop carries an assembly plate 36 which is rigidly connected to a shaft 31 Journaled in the upper end of the bracket piece 33a and in a third bracket piece 38 also carried by the platform 32.

- For the purpose of imparting rotary movement to the shaft 31, and through this shaft to the elevation finding loop 26, a worm gear 39 is rigidly mounted upon the shaft 31. This gear meshes with a driving worm 40 which is suitably jourtheir upper ends, pivotally support the ends of the naled in a U-shaped bracket 4| mounted upon the upper end of the bracket piece 26, and is connected by means of a flexible shaft 42 with the motor shaft extension |1b of the worm shaft "a. By virtue of this arrangement, a substantially rigid drive connection is provided between the worm shaft Ho and the elevation finding loop 26. In the assembly of this drive connection the parts are so arranged and adjusted that the angle of elevation between the elevation finding loop 26 and a true horizontal plane is exactly the same as the angle of elevation between the gun l0 and a true horizontal plane.- Moreover, the driving ratio between the worm l1 and the shaft H is exactly equal to that between worm 40 and the shaft 31, whereby the angular positions of the gun barrel Ill and the loop 26 with respect to true horizontal are maintained exactly the same during movement of the gun barrel iii to bear on a selected target.

As indicated above, the direction finding loop 21 is carried by a frame 28 which is rotatable about the central pedestal 3| of the base 29. More specifically, this frame, at the central portion thereof, is supported upon a flanged sleeve 43 which carries a worm gear 44 intermediate the two flanges thereof. This gear meshes with a driving worm 45 suitably journaled in a bracket piece 46 carried by the base 29, and is connected by means of a flexible shaft 41 to the shaft extension 23b of the rotor shaft 23a. As thus ar-' ranged, a positive drive connection is provided between the rotor shaft 23a and the frame 28 upon which the direction finding loop 21 is mounted. In the assembly of the apparatus the parts of this drive connection are so arranged and adjusted that the vertical plane cutting the direction finding loop 21 is exactly parallel with the vertical plane cutting the gun barrel In. Moreover, the driving ratio between the worm 23 and the gear 20 is exactly the same as the drive ratio between the worm 45 and the gear 44, whereby the parallel vertical relationship between the direction finding loop 21 and the gun barrel I0 is 1- maintained during operation of either of the motors 2| and 22 to drive the pedestal l2 to a new traverse position.

In order to render the frame 28 readily rotatable'about the pedestal 3|, suitable anti-friction bearings 48, 49 and 50 are provided between the sleeve 43 and the stationary parts of the structure. More specifically, the central pedestal 3| has telescoped thereover a flanged sleeve 6| which bears against the upper Side of the base 29. The flanged portion of this sleeve carries a hearing ring 52 having a ball race therein in which the anti-friction balls 50 are disposed. This bearing ring also supports a series of assembly .and spacing rings 53, 54, 55, 56 and 51 which are telescoped over the sleeve 5|. The last of these series of rings is flanged outwardly at its upper end to provide an extended surface for supporting the platform 32.

The sighting piece 25 is supported upon the top supporting plate 58 of the centrally disposed pedestal 3|. More specifically, the supporting plate 58 carries a U-shaped bracket piece 59 having its legs extending downwardly, and a second U-shaped bracket 60 is pivotally mounted upon the bracket 59 with its legs extending in a vertical direction to provide a support for the sighting piece 25. As best shown in Fig. 4 of the drawings. a shaft 6| extending vertically through registering openings in the plate 58 and the base portions of the two U-shaped members 59 of the bracket is utilized to provide a pivot point about which the bracket ll may be rotated. A suitable anti-friction washer I2 is provided between the adjacent surfaces of the two bracket pieces 80 and to facilitate rotation of the bracket 0. relative to the bracket II in a horizontal plane. The sighting piece 25, which is shaped as a shotgun having a stock 284. is mounted for rotation about a shaft 63 which is suitably journaled in the oppositely disposed legs of the bracket 60. The sighting piece is hollow and preferably is formed of a light metal, such as aluminum. Its oppositely disposed vertically extending side walls are iournaled on the shaft M so that the entire piece is readily rotatable about this shaft. In order to. bring the sighting piece It to bear in a desired direction and, more particularly, to point this piece at a target, it is equipped at the front and rear ends of the barrel portion thereof with front and rear sights 28b and We, respectively.

An optical system is mounted within the sighting piece 25 for projecting a beam of light alon the line of sight thereof. This optical system comprises a light ource in the form of an incandescent lamp M, a deflecting mirror 65 for transmitting the light produced by the larnp 84 along the barrel of the sighting piece, and a converging lens 66 for controlling the width of the light beam projected from the front end of the sighting piece. The three enumerated elements may be mounted within the sighting piece 25 in the illustrated positions thereof in any suitable manner.

For the purpose of controlling the driving motors it, it, if and 22 in the manner more fully described below, .two circuit control devices are provided which are respectively controlled in accordance with the vertical and horizontal rotation of the sighting piece 25. The first of these devices comprises a pair of contact elements 61 and 6% which are assembled between insulating strips it and are rigidly mounted for rotation with the shaft 63 by means of a clamping assembly which includes two clamping plates l0 and H and a pair of clamping screws 12 and ii. The two contact elements El and 6b are arranged to cooperate with a third contact element It which is assembled between two insulating pieces 15 and is mounted upon the upper under surface of the sighting piece it by means of a supporting column it, a clamping ring 11 and an assembly screw it. As thus arranged, when the sighting piece 25 is manually rotated initially in a clockwise direction about the shaft 83 to increase the angle of elevation thereof, the stiff contact element it is moved to bring the contact carried by the free end thereof into engagement with the contact carried by the free end of the contact element M. During such movement ofthe sighting piece 25 the shaft 63 does not rotate. When, however, the adjacent contacts carried by the two contact elements it and B1 are engaged, the two contact elements 51 and lit, together with the shaft M, are thereby cons-trained to rotate with the sighting piece 25 for a purpose hereinafter explained. Conversely, when the sighting piece it is pivoted in a counterclockwise direction about the shaft 53 to decrease the angle of elevation thereof. the lower contact carried by the element It is moved to engage the contact carried by the element after which the sighting piece 25 and the shaft '63 are rotated in unison for a purpose hereinafter explained. In this regard it is noted that suitable spring-biased friction means may be provided between the shaft it and the legs of the bracket 80 to insure that the shaft 88 will not be rotated until the contact carried by the element 14 is moved to engage one of the contacts carried by the associated contact elements 61 and II. This spring-biased friction means may have various forms but may conveniently be constructed as shown in Figs. 8 and 9 where the shaft 63, shown as being journaled in the side legs of the bracket 60 and in the side walls of the sighting piece 25, has applied thereto a friction brake comprising two brake shoes We and 98b, the former of which is secured to one of the side walls of the sighting piece on the inner side thereof. These shoe members are connected by bolts 81 and wing nuts 98 and a spring 99 is mounted on each bolt between the lower floating shoe 96b and the wing nut so that by adjusting these nuts the normal compression of these springs 99 may be adjusted to produce the desired frictional resistance to the rotation of the shaft 83.

The other circuit control device, 1. e., that which responds to rotation of the sighting piece 25 in the horizontal plane, is arranged to be controlled by relative movement between the bracket 50 and the shaft 6i. This device comprises a pair of contact elements 19 and 80 which are assembled between the insulating strips 8i and are rigidly mounted upon the upper end of the shaft Si by means of a clamping assembly which comprises the two clamping plates 82 and 83 and the assembly screws a l and 85. The two contact elements l9 and 80 are arranged to cooperate with a third con-tact element 88 which is clamped between the two insulating strips 81 and is mounted upon an outwardly projecting portion 80a of the bracket 60 by a mounting assembly which includes the column 88, a clamping ring 99 and an assembly screw 90. As thus arranged, the contact carried by the free end of the contact element 86 is moved to engage the contact carried by the free end of the element 19 during preliminary rotation of the sighting piece 25 about the shaft Bl. After these two contacts are engaged, the shaft ti is rotated with and by the sighting piece 25. Conversely, if the sighting piece is rota-ted in a counterclockwise direction about the shaft 8 I, the contact carried by the element 86 is moved to engage the contact carried by the element 80, after which the sighting piece and the shaft 6| are thereby constrained to rotate in unison. Here again it is pointed out that suitable spring-biased friction means, similar to that shown in Figs. 8 and 9, may be used to insure relative rotation between the brackets 60 and 59 until such time as the contact carried by the contact element 36 is moved to engage the contact carried by one of the two coacting elements it and 80.

Further to consider the arrangement of the control apparatus as shown in Figs. 2 and 3 of the drawingsit may be pointed out that the light beam as projected along the line of sight of the sighting piece 25 by the optical system mounted within this sighting piece is utilized as a vehicle to arrest the traverse and elevational movements of the gun barrel Hi When this barrel is brought to bear in the direction established by the line of sight of the sighting piece. To this end, the exploring bands or loops 2t and 21 are constructed to form light sensitive elements. Each of these bands is shaped :to form an exact semi-circle, the true center of which is coincident with the corresponding center of rotation of the sighting piece 25. Thus the center of the elevation finding band 20 coincides with the point about which the sighting piece 20 may be rotated in a horizontal direction or a vertical azimuth direction. The center of the semi-circular .direction finding band 21 also exactly coincides with this point.

Preferably, each of the two bands 20 and 21 is constructed in the manner shown in Fig. 6 of the drawings. Briefly considered, this construction comprises two semi-circular strips i and 82 formed of copper or other conductive material, which are held in spaced apart relationship by means of a semi-circular spacing element 03 formed of suitable insulating material. The three pieces BI, 02 and 03 are held in assembled relationship by means of an assembly ferrule 80 which may be formed of Bakelite or other mouldable insulating material. The inner surface of the spacing element 93 is provided with a coating or layer of light sensitive material 80, such, for example, as selenium. As thus constructed, it will be understood that the electrical resistance between the two strips 3| and 02 is a function of the intensity of light impinging upon the light sensitive layer 90. This resistance is sharp ly decreased in response to a change in 'the-intensity of the light striking the light sensitive layer 05 at any point therealong. Thus if the light beam projected along the lineof sight of the sighting piece strikes a segment of the layer 30, the electrical resistance between the two conductors 0| and 92 is rapidly and sharply lowered.

In utilizing the sighting piece 25 and the two exploring bands 28 and 21 to control the operation of the four motors I0, I0, 2| and 22, the circuit network shown in Fig. 7 of the drawings may be employed. In this network the four motors are shown as being connected for energization from a. suitable source of alternating current indicated by the bracketed terminals 06. The four motors are respectively arranged for energization under the control offour relays I40, I50, I80 and I10. These relays, in turn,'are arranged to be controlled by the contact elements 81, 88, 10, 19, 00 and 86 of the two circuit controlling devices and by a pair of stop relays I20 and I30. Bridge-type of control circuits are utilized for controlling the energization of the two stop relays I20 and I30. More specifically, the exploring band 26 is arranged to control the energization of the stop relay I20. To this end, the electrical resistance between the two conductive strips of the band 28 is connected through the electronic control device I04 to control the energization of the right-hand winding of a differentially wound relay I00. The other winding of this relay is arranged to be energized in the output circuit of a second electronic control device I02 having its input circuit connected to include the resistance between the conductive elements of a balancing band 28a hereinafter more fully described. Ad-

justable resistors I03 and I08 are respectively provided in the circuits through which the two windings of the relay are energized, in order normally to equalize the currents traversing these two windings. In a similar manner a differentially wound relay H0 is provided directly to control the energization of the stop relay I30;

The energization of the left-hand winding of thisrelay is arranged to be controlled through an electronic control device H4 in accordance with the resistance between the conductive strips'of the exploring band 21, while the opposite windinaccordance with the resistance'betweeii the ing of this. relay is arranged to be controlled through a fourth electronic control devicelll conductive strips of a balancing band 21a. .Adiustable resistors H3 and 8 are respectively included in the circuits for energizing the windings of the relay H0 in order that thesewindinga may normallyrbeenergized by currents of th same magnitudes At this point it is noted that the construction and characteristics of two balancing bands 20:: and 210 located in the vicinity of the bands 20 and 21 exactly duplicate the construction and characteristics of the bands 28 and 21, respectively. Moreover, these two balancing bands are exposed to the same ambient temperature and light conditions as the exploring bands 20 and 21 but are not exposed to the light beam emitted by the sighting piece. While in the illustrated em+ bodiment of the invention the balancing bands 28a and 21a are shown rigidly supported in parallel relationship in a horizontal plane by the two upstanding columns 20a and 20b, it should be understood that the balancing bands maybe supported in any manner so long as'they are ex posed to substantially the same ambient'temperature and light conditions as the movable exploring bands 28 and 21,- By virtue of this arrangement, changes in the ambient temperature and light conditions to which the exploring bands 20 and 21' are subjected are prevented from producing a, false response of the differential relays I00 and H0. Thus, if the resistance between the conductive strips of the band 28, for example, is decreased, due to a change in the temperature or the intensity of the light other than the light from the sighting piece 25 impinging upon the light sensitive surface thereof; thereby to produce an increasein the current flow through the right winding of the relay I00, the resistance be-; tween the conductive strips of the balancing band 280. is correspondingly decreased to-produce a corresponding increase in the current flow through the left winding of the relay I00." The relay is thus prevented from falsely operating. The same type of balancing action is produced by the balancing band 21a associated with the exploring'band 21-. Current for energizing the relays I20, I30, I40, I50, I00 and'I10, and for controlling the therm ionic elements of the four control devices I02; I00, H2 and I may be supplied from any suitable direct current source of the proper potential. In the interests of facilitating a description of the circuits involved, this source has not been shown. It will be understood, however, that the positive terminal of the source is connected to each of the points of the illustrated circuit indicated by the ground symbol and that the negative terminal oi the source is connected to each of the relay winding terminals identified by the negative polarity sign. y In considering the operation of the apparatus described above, it may be assumed that the sighting piece 28 is pointing in a particular di-- rection, that the lamp 00 is energized to project a light beam along. the line of sight of the sighting piece, and that the exploring bands 23 and 21 both occupy positions wherein the light sensi-' tive layers thereof are intersected by the light' beam. In this regard it is noted that" the cross-- sectional area of the light beam as measured at the point of intersection with the overlapped portions of the two bands 28: and '21 is suflicientthe beam. The correct cross-sectional dimensions of the light beam .at this point may be de--.

termined by using a converging lens having the proper optical properties.

Under the conditions stated, the resistance between the conductivev strips of the exploring band 20 is considerably less than the resistance between the conductive strips of the balancing band 20a, which is not exposed to the light beam. Accordingly, the right winding of the diilferential relay I00 is energized by a current of substantially greater magnitude than that traversing the left winding of this relay, and the relay occupies its operated position. With this relayoperated, an obvious circuit is completed through the contacts I M for energizing the stop relay I20. With the relay I20 in its operated position. the operating circuits for the two relays I40 and I00 are held open at the contacts I2I, the latter contacts being normally biased into closed circuit position. In a similar manner, with the light sensitive layer of the exploring band 21 exposed to the light beam produced by the lamp 60 and projected along the line of sight of the sighting piece 20, the resistance between the conductive strips of the band is substantially lower than the resistance between the conductive strips of the balancing band 21a. Accordingly, the left winding of the relay H0 is energized by a current of substantially greater magnitude than that traversing the right winding of this relay, and the relay is operated. With-the relay H0 in its operated position, an obvious circuit is completed through the contacts III for energizing the stop relay I30. With the latter relay operated the operating circuits for the two relays I00 and I10 are held open at the contacts IOI, the latter contacts being normally biased into closed circuit position.

It with the four relays I00, IIO, I20 and I30 operated, the sighting piece 20 is manually rotated in azimuth about the shaft M in a clockwise direction and about the shaft 00 in elevation in a clockwise direction in bringing it to bear on a target, the contacts carried by the contact elements 01 and 10 are engaged, the contacts car- .ried by the contact elements 19 and 00 are moved into engagement, and the light beam projected along the line of sight of the sighting piece is shifted so that it no longer cuts the two exploring bands 28 and 21. Incident to these operations, the operating circuit for the relay I00 is prepared at the contacts carried by the two elements 01 and 14, the operating circuit for the relay I10 is prepared at the contacts carried by the two elements 10 and 06, the current traversing the right winding of the relay I00 is decreased until it equals that flowing through the left winding of this relay, and the current traversing the left winding of the relay IIO is decreased until it equals that flowing through the right winding of this relay. Thus the two relays I00 and H0 are caused to restore or deenergize the relays I20 and I30, respectively. The relay I20, in releasing, closes its contacts I2I to complete the prepared circuit through the contact elements 10 and B1 and the contacts I5I for energizing the relay I40. The relay I30, in releasing, closes its contacts Hi to complete a circuit through the contact elements 06 and 19 and the contacts I62 for energizing the relay I10.

The relay I40, upon operating, locks to ground through the contacts IOI and I2I and, at its contacts I42, opens a point in the operating circuit for the relay I50, thereby to prevent the latter relay from being energized until the relay I40 is deenergi'zed. At its contacts I43, the relay I40 completes an obvious circuit for energizing the motor I0. The relay I10, upon operating, locks to ground through the contacts I12 and I0I and, at its contacts I1 I, opens a point in the operating circuit {or the relay I00, thereby to prevent the latter relay from being energized until the operated relay I10 is deenergized. At its contacts I13, the relay I10 closes an obvious circuit for energizing the motor 22.

With the motors I0 and 22 operating, the gun barrel I0 is rotated with the shaft II to increase the angle of elevation thereof and the pedestal I2 is rotated to swing the gun barrel in a clockwise direction. Thus the gun I0 is moved in a direction tending to bring it back into parallelism with the line of sight of the sighting piece 20. Incident to the operation of the motor l0, the exploring band 20 is, through the driving connection comprising the flexible shaft '42, the worm 00, the worm gear 39, and the shaft 21, rotated in a direction to increase the angle of elevation thereof, it being again noted that this driving connection serves to maintain the same angle of elevation for the exploring band 20 and the gun barrel I0. Incident to the operation of the motor 22 to drive the pedestal I2 in a clockwise direction, the direction finding band 21 is, through the action of the driving connection comprising the flexible shaft 41, the worm 00 and the worm gear 40, rotated in a clockwise direction about the pedestal 0|. In this case, also, the gun barrel I0 and the band 21 are rotated at the same speeds to maintain a parallel relationship between the vertical planes cutting these two elements.

When the elevation finding band 20 is moved to a position where it cuts the light beam projected along the line of sight of the sightingpiece 25, the relay I00 is again caused to operate in a manner clearly apparent from the above explanation. This relay, in operating, again closes its contacts IN to energize the relay I20 and the latter relay, upon operating, opens its contacts I2I t deenergize the relay I00. The relay I40, upon restoring, opens its contacts I40 to deenergize the motor I 0 and thus arrest the movements of the exploring band 26 and the gun barrel III in the vertical direction. At its contacts I42, the relay I00 reprepares the operating circuit for the relay I50. At its contacts I4I, the relay I00 opens its own locking circuit.

When the direction finding band 21 is moved to cut the light beam projected along the line of sight of the sighting piece 25. the relay H0 is caused to reoperate in a manner clearly apparent from the preceding-explanation. In operating, this relay closes its contacts III to energize the relay I30. The latter relay, upon operating, opens its contacts I3I to deenergize the relay I10. When the relay I10 restores. it opens its contacts I13 to deenergize the motor 22 and thus arrest the horizontal movements of the gun barrel I0 and the exploring band 21. At its contacts I12, the relay I10 opens another point in its own locking circuit. At its contacts IN, the relay I10 reprepares the operating circuit for the relay I60. Following the operations just described the gun barrel I0 is pointing in the direction established by the line of sight of the sighting piece 25, in readiness for firing. A suitable fire control circuit connecting the illustrated control equipment with the electromagnetlcally controlled firing mechanism of the gun, may be utilized to eilect the firing operation. In this regard it will be understood that the operator of the control ll equipment, upon observing that movement of the two exploring bands 26 and 21 has stopped, is informed that the gun barrel I has been brought to bear on the target selected by aiming the sighting piece 25 and, hence, that the firing operation may be started.

To consider another example of the manner in which the control equipment may be operated, it may be assumed that the sighting piece 25 is rotated about the shaft 63 in a direction to decrease the angle of elevation thereof and counterclockwise about the shaft 6| to swing the muzzle of the sighting piece to the left. In response to this operation, the contacts carried by the two contact elements 65 and 14 are engaged, the contacts carried by the two contact elements and 80 are engaged, and the two relays I20 and I30 are deenergized, all in a manner clearly apparent from the preceding explanation. Incident to these operations, a circuit is completed through the contacts I2I, the contact elements 14 and 68, and the contacts I42 for energizing the relay I50. Concurrently therewith, a circuit is completed through the contacts IOI, the contact elements 66 and 80 and the contacts |1I for energizing the relay I60. The relay I50, upon operating,'locks to ground through the contacts I52 and I'll; opens its contacts I5I to interrupt the operating circuit for the relay I40; and closes its contacts I59 to energize the driving motor I9 in an obvious circuit. The relay I60, upon operating, locks to ground through the contacts I5I and I3I; opens its contacts I62 to interrupt an incomplete operating circuit for the relay I10; and closes its contacts I63 to energize the driving motor 2|. With the two motors I9 and 2| operating, the muzzle of the gun barrel I0 is moved to the left and downward from its previous setting, and this movement is accompanied by corresponding changes in the positions of the two exploring bands 26 and 21. When these two bands have been re-positioned under the control of the two motors I9 and 2| ,so th-atthey again out the light beam transmitted along the newly established line of sight of the sighting piece 25, the two relays I00 and H0 reoperate to cause the reoperation of the relays I20 and I30. The two relays I20 and I30 respectively function to deenergize the two operated relays I50 and I60. The relay I50, upon restoring, opens its contacts I58 to deenergize the driving motor I9, whereby movement of the exploring band 26 and movement of the gun barrel I0 in the vertical direction is arrested. At its contacts I52, the relay I50 opens another point in its own locking circuit. At its contacts I5I, the relay I50 reprepares the operating circuit for the relay I40. The relay I60, upon restoring, opens its contacts I68 to deenergize the motor 2|, whereby movement of the exploring band 21 and movement of the gun barrel I0 in the horizontal direction are arrested. At its contacts I62, the relay I60 reprepares the'operating circuit for the relay I10. At its contacts I5I, the relay I60 opens another point in its own locking circuit. Following the operations just described the gun barrel I0 is pointing in the direction established by the line of sight of the sighting piece 25.

From the above explanation it will be understood that the four motors I8, I9, 2| and 22 may be energized in different combinations under the control of the four relays I40, I50, I60 and I10 to drive the gun barrel I0 and the two exploring bands 26 and21 toward any new position established by movement of the sighting piece 20 to a-new setting. For example, if the muzzle of this sighting piece is swung upward and to the left, the two relays I40 and I50 are energized to cause the operation of the two m0- tors I0 and 2|, whereby the two exploring bands and the gun barrel I0 are operated to follow the movementof the sighting piece. On the other hand, if the muzzle of the sighting piece is moved downward and to the right, the relays I50 and I10 are energized to cause the operation of the two motors I9 and 22 and the consequent movement of the two explorin bands and the gun barrel I0 to the new position established by the sighting piece. Itis also possible with the illustrated arrangement that only one of the four motors may be energized in response to a given change in the setting of the sightin piece 25. Thus if the muzzle of this piece is swung to the left without in any way altering the angle of elevation thereof, the two relays I40 and I50 remain deenergized to prevent the operation of the two motors I8 and I9 and onl the relay I50 is energized to effect the operation of the motor 2 I.

The purpose of providing the described locking circuits for the four relays I00, I50, I00 and I10, is to permit small final adjustments of the sighting piece 25 without disturbing the operation of the energized driving motor or motors to move the gun barrel I0 and the two exploring bands in the general direction required to establish settings for these elements which correspond to the final setting of the sighting piece. In this regard it will be understood that if the sighting piece is pivoted back and forth about the axis of the shaft 68, the contact carried by the contact element 14 is alternately moved to engage the contacts carried by the contact ele ments 61 and 68. This type of movement of the sighting piece may well be required during the final adjustment of the piece to a new setting. In the absence of the described locking circuits, however, the one of the two motors I8 and I8 energized during the initial movement of thesighting piece to its new setting could be broken during final adjustment of the sighting piece toprematurely stop the movement of the exploring band 26 and the gun barrel I0 in the vertical direction. This difliculty is obviated by providing the described locking circuits for by-passing the contact elements 61, 68, and 14.

The described cut-oil contacts I42, I5I, I02,

and "I of the relays I40, I50, I60 and I10 are provided to prevent simultaneous energization of the two motors I8 and I9 'or simultaneous energization of the two motors 2| and 22. In the absence of these contacts it would be possible, during the final adjustment of the sighting piece 26 to a new setting and the consequent alternate engagement-of the contact element 14, for example, with the two contact elements 61 and 60, to establish circuits for energizing both of the relays I40 and I50. In such case both of the motors I6 and I9 would be energized to arrest the movement of the gun barrel I0 and the exploring band 26. By virtue of the described arrangement, however, it is impossible for more than one of the relays I40 and I50, or more than one of the two relays I60 and I10, to be energized at the same time.

The response of the illustrated control equipment is sufliciently fast to insure the energization the sighting piece may be tilted in the direction required to cause the operation of the two relays MW and IN and the two motors l8 and 2|. and immediately thereafter the direction of movement thereof ma be reversed so that the light beam projected along the line of sight of the sighting piece only momentarily cuts the two exploring bands 26 and 21 during the reverse movement of the sighting piece. In such case the two relays Mil and I30 are momentarily operated to cause the deenergization and release of the two relays lit and IM and consequent deenergization of the two motors l8 and 2i during the short time interval that the light beam cuts the two exploring hands during the reverse movement of the sightin piece. Immediately thereafter, the two relays I20 and IN are deenergized and restore to establish circuits for energizing the other two relays I50 and ill! with a consequen energization of the two other driving motors I and 22, whereby the direction of movement of the gun barrel w and the two exploring bands is reversed to follow the reverse movement of the sighting piece. It will be noted that the terms "exploring band" and exploring means" as used in the foregoing description and in the claims are intended to refer to a device, such as one of the bands 26 or 21!, which has primarily a follow-up function in that it follows the movements of another member suchas the gun. This exploring band may be a light sensitive device and have circuit controlling functions as set 'forth in certain of the claims.

While one embodiment of the invention has been disclosed, it will be understood that various modifications may be made therein which are within the true spirit and scope of the invention.

What is claimed is:

1. In apparatus for sighting a gun, exploring means, a sighting piece adapted to be brought to bear on a target, means for moving said exploring means and said gun in unison until said gun is brought to a position wherein its line of sight is parallel to the line of sight of said sighting piece, and means controlled by the coincidence of the line of sight of said sighting piece upon a part of said exploring means for arresting the movement of said gun when its line of sight is brought into said parallel relationship.-

2. In apparatus for sightin a gun, exploring means, a sighting piece adapted to be moved to a position wherein it bears on a. target, means responsive to the movement of said sighting piece for moving said gun in a direction to bring it to a position wherein its line of sight is parallel to the line of sight of said sighting piece, means for moving said exploring means in unison with said gun, and means controlled by the coincidence of the line of sight of said sighting piece upon a part of said exploring means for arresting the movement of said gun when its line of sight .is brought into said parallel relationship.

3. In apparatus for sighting a gun, a movable sighting piece adapted to be brought to bear on a target, exploring means normally positioned in coincidence with the line of sight of said sighting piece, driving means for operating said gun in any direction and for operating said exploring means in unison with the operation of said gun, means for initiating the operation of said driving "sive to movement of said sighting piece for selectively controlling said driving means sothat said exploring means is moved toward a position of coincidence with the newline of sight of said sighting piece, and means operative to arrest the operation of said driving means when said exploring means attains a position of coincidence with the new line of sight of said sighting piece.

5. In apparatus for sighting a gun, a movable sighting piece adapted to be brought to bear on a target and including means for projecting a light beam along the line of sight thereof, movabie light sensitive exploring means adapted to be controlled by said light beam, and means controlled by said exploring means for moving said gun to cause its line of sight to be parallel to the line of sight of said sighting piece.

6. In apparatus for sighting a gun, a movable sighting piece adapted to be brought to bear on a target and including means for projecting a light beam along the line of sight thereof, movable light sensitive exploring means adapted to be energized when moved into said light beam, means for moving said gun and said exploring means in unison, and means responsive to the energization of said exploring means for arresting the movement of said gun.

'I. In apparatus for sighting a gun, driving means for changing the traverse and elevation of said gun respectively, exploring means comprising traverse and elevation exploring bands, means controlled by said driving means for operating said bands so that the positions thereof correspond to the traverse and elevation of said gun, a movable sighting piece adapted to be brought to bear on a target, means for starting said driving means, and means controlled by said sighting piece and said bands for stopping said means to operate said exploring means toward a position of coincidence with a newly established line of sight of said sighting piece, and means for automatically arresting the operation of said driving means when said exploring means is driving means as said exploring bands are respectively operated to intersect the line of sight of said sighting piece.

8. In apparatus for sighting a gun, driving means for changing the traverse and elevation of said gun respectively, exploring means comprising traverse and elevation exploring bands, means controlled by said driving means for operating said bands so that the positions thereof correspond to the traverse and elevation of said gun, a movable sighting piece adapted to be brought to bear on a target, means responsive to movement of said sighting piece from one position to a new position for starting said driving means, and means controlled by said sighting piece and said bands for stopping said driving means as said exploring bands are respectively operated to intersect the line of sight of said sighting piece.

9. In apparatus for sighting a gun, driving means for changing the traverse and elevation of said gun respectively, exploring means comprising llght sensitive traverse and elevation exploring bands, means controlled by said driving means for operating said bands so that the positions thereof correspond to the traverse and elevation of said gun respectively, a movable sighting piece adapted to be brought to bear on a target and including means for projecting a' light beam along the line of sight thereof, means for starting said driving means, and-means-co'ntrolled by said bands for stopping said driving means as said bands are respectively operated to intersect said light beam.

10. In apparatus for sighting a gun, driving means for changing the traverse and'elevationo'f said gun respectively, exploring means comprising light-sensitive traverse and elevation exploring bands, means controlled by said driving means -for operating said bands so that the positions thereof correspond to the traverse and elevation of said gun respectively, a movable sighting piece adapted to b brought to bear on a target' and including means for projecting alight beam along the line of sight thereof, means responsive to movement of said sighting piece from one position to a new position for starting said'driving means, and means controlled by said bands for stopping said driving means as said bands are respectively operated to intersect said light beam.

11. In apparatus for sighting a gun," driving means for changing the position of said gun, a

light sensitive exploring band having a resistance which changes in accordance with light intensity, means controlled by said driving means for operating said band so that the position thereof corresponds to the position of said gun, a movable sighting piece adapted to be brought to bear on a target and including means for projecting a light beam along the line of sight thereof, means for starting said driving means, whereby said exploring band is operated to intersect said light beam, and means responsive to the resulting change in resistance of said band for stopping said driving means.

12. In apparatus for sighting a gun, driving means for changing the position of said gun, a light sensitive exploring band having a resisttime which changes in accordance with light intensity, means controlled by said driving means for operating said band so that the position there- 01' corresponds to the position of said gun, a movable sighting piece adapted to be brought to bear on a target and including means for projectin a light beam along the line of sight thereof, means responsive to movement of said sighting piece from one position to a new position for starting said driving means, whereby said exploring band is operated to intersect said light beam, and means responsive to the resulting change in re,-

sistance of said band for stopping said driving.

means.

13. In apparatus for sighting a gun, drivin corresponds to the position of said gun, a movable sighting piece adapted to be brought to bear on a target and including means for projecting a light beam along the line of sight thereof, means for starting said driving means, whereby said exploring band is operated to intersect said light beam, means responsive to the resulting change in resistance of said band for stopping said driving means, and means for preventing said lastnamed means for responding to changes in the' resistance of said exploring band which result from changes in the temperature 01' saidv band and changes in the ambient light conditions surrounding said band.

14. In apparatus for sighting a gun, driving means for changing the position of said gun, a light sensitive exploring band having a resistance which changes in accordance with light intensity, means controlled by said driving means for operating said band so that the position there of corresponds to the position of said gun, a movable sighting piece adapted to be brought to bear ona target and including means for projecting a light beam along the line of sight thereof, means responsive to movement of said sighting piece from one position to a new position for starting said driving means, whereby said exploring band is operated to intersect said light beam, means responsive to the resulting change in resistance of said band for stopping said driving means, and means for preventing said last-Z named means from responding to changes in the resistance 01 said exploring band which result from changes in the temperature of said band and changes in the ambient light conditions surrounding said band,

15. In apparatus for sighting a gun, driving means for changing the position of said gun, a light sensitive exploring element havinga resistance which changes with light intensity, means controlled by said driving means for operating said element so that the position thereof corresponds to the position of said gun, a light sensitive balancing element having substantially the same characteristics as said exploring element, a relay comprising a pair of dliierentially related windings, means for controlling the energization of one of said windings in accordance with the resistance oi said exploring element, means for controlling the energization of the other of said windings in accordance with the resistance 01 said balancing element, a movable sighting piece adapted to be brought to bear on a target and including means for projecting a beam of light along the line of sight thereof, means for starting said driving means, whereby said explorin band is operated to intersect said light beam, the change in resistance of said exploring element resulting from the intersection of said beam by said exploring element being eflective to cause the operation of said relay, and means responsive to the operation of said relay for stopping said driving means.

16. In apparatus for sighting a gun, driving means for changing the position of said gun, a light sensitive exploring element having a resistance which changes with light intensity, means controlled by said driving means for operating said element so that the position thereof corresponds to the position 01 said gun, a light sensitive balancing element having substantially the same characteristics as said exploring element, a relay comprising a pair of differentially related windings, means for controlling the energization of one of said windings in accordance with the resistance of said exploring element, means for controlling the energization of the other of said windings in accordance with the resistance of said balancing element, a movable sighting piece adapted to be brought to bear on a target and including means for projecting a beam of light along the line of sight thereof, meansresponsive to movement of said sighting piece from one po-' sition to a new position for starting said driving means, whereby said exploring band is operated to intersect said light beam, the change in resistance of said exploring element resulting from 17 said relay, and means responsive to the operation of said relay for stopping said driving means.

WM. WALTER OWEN, Executor of the Estate of Bernard D, Willis,

' Deceased.

REFERENCES CITED UNITED STATES PATENTS Name Date Maxim July 23, 1989 Number Number Name Date Droitcour Feb, 18, 1930 Young May 1, 1934 Brady Mar. 17, 1936 FOREIGN PATENTS Country Date Great Britain 1911 Great Britain Jan. 3, 1935 Great Britain Oct. 6, 1937 Great Britain Mar. 28, 1938 Germany Jan. 27, 1920 France Aug. 26, 1935 

